A blind guy driving a car? That was the latest step in Google's two-year-old program to develop a self-driving car.

A video released last week on YouTube shows Steve Mahan, who is almost totally blind, behind the wheel of a Toyota Prius, running errands to Taco Bell and the dry cleaners.

"Look Ma, no hands, and no feet!" Mahan says as the car steers autonomously along a carefully planned route. "This is some of the best driving I've ever done."

Google announced its self-driving car project in 2010, building on research started by a Stanford University that won a $2 million Defense Advanced Research Projects Agency challenge.

Although the Google demonstration followed a preplanned route, it shows the potential for such cars to work without extensive preparation, said spokesman Jay Nancarrow. But he said the company was not prepared to detail the vehicle's capabilities and limitations.

Autonomous cars outfitted with radar and laser sensors like the Prius would be liberating to people such as Mahan, who cannot drive on his own. “Where this would change my life would be to give me the independence and the flexibility to go to the places I both want to go and need to go, when I need to do those things,” Mahan said after his day in the car, which took place in January.

Even those without vision loss could benefit from the automation of driving because computer-controlled cars would be able to drive in close formation to increase the traffic capacity of existing roads, said Google project leader Sebastian Thrun. This would save Americans 4 billion hours of wasted time and 2.4 billion gallons of gasoline, he estimated.

Thrun spoke at the TED conference last year about his personal motivation to develop a self-driving car. “As a boy I loved cars,” he said. “When I turned 18 I lost my best friend to a car accident. Then I decided I would dedicate my life to saving 1 million people every year."

Tangi Quemener / AFP/Getty Images

Junior, a 2006 Volkswagen Passat, heavily modified and robotized by a team of Stanford University, crosses the finish line in first place of the DARPA Grand Challenge on Nov. 3, 2007, in Victorville, Calif.

His effort started with Stanley, a Volkwagen station wagon outfitted with sensors, which in 2005 was the first vehicle to complete DARPA’s challenge course.

“Since then our work has focused on building cars that can drive anywhere by themselves,” he said.

“Our cars have sensors with which they magically can see everything around them and make decisions about every aspect of driving. It is the perfect driving mechanism. We’ve driven in cities, like in San Francisco here. We’ve driven from San Francisco to Los Angeles on Highway 1. And even crooked Lombard Street in San Francisco.”

Another video shows the Google autonomous Prius ripping through a snaking course of orange cones in a parking lot. This capability suggests the autonomous car need not proceed at the pace of a driver's ed student.

Finally drivers would be able to focus on things they’ve already shown are more important to them than watching the road, like talking on the phone, texting friends, checking Facebook, eating and personal grooming. Maybe they could watch the YouTube video of the blind guy in the driver's seat.